Rates of relatively uncommon cancer have increased

Dear Doctor: A friend of mine was diagnosed with, and treated for, anal cancer about two years ago. She never told me the location of her cancer until recently because she thought that "anus" and "anal" were shameful words. She also let the symptoms drag on for a year or so because she thought they were due to hemorrhoids. What are the symptoms, how is this type of cancer treated, and is it on the increase?

Dear Reader: In our everyday life, we focus on our usual responsibilities: our family, our job, paying our mortgage or rent, maintaining friendships, worrying about politics, etc. This complex existence often doesn't afford us time to deal with nagging symptoms. When those symptoms occur in a part of the body that people don't like to consider, like the anus, the likelihood of a delay in diagnosis increases.

Also, anal cancer is relatively uncommon, meaning people are unlikely to suspect the disease. Each year, it's diagnosed in approximately 8,200 people in the United States, leading to about 1,100 deaths; only about 0.2 percent of the population will be diagnosed with it over their lifetime. But to answer your last question: Even though the numbers are small, yes, the rate of anal cancer is increasing. Compared to diagnoses 40 years ago, the rate of anal cancer has increased three times in men and 1.7 times in women. As with cervical cancer, infection with the human papillomavirus (HPV) increases the risk, as does homosexuality (for men), anal sex and a history of anal warts.

As for symptoms, anal bleeding occurs in 45 percent of patients but, because hemorrhoids can similarly cause bleeding, people often can ignore this sign. Anal pain or a sensation of fullness in the rectum occurs in about 30 percent of patients, and 20 percent of patients have no symptoms at all.

In the 1960s, treatment consisted of the removal of the anus and the surrounding tissues, leading to a permanent colostomy, that is, a rerouting of the colon through an opening in the abdomen. Three percent of patients died from the procedure alone.

Today, treatment consists largely of radiation and chemotherapy. The radiation therapy is generally given in 25 treatments over a period of five weeks. The chemotherapy -- typically, 5-fluorouracil and Mitomycin (or cisplatin) -- is often given on the first and fifth weeks of radiation treatment. This combined approach has decreased not only the death rate from anal cancer, but also the need for a colostomy. Today, only 14 to 35 percent of patients need a colostomy after five years. Survival rates depend on the tumor size at diagnosis. The five-year survival rate ranges from 86 percent to 42 percent, depending on the severity of the disease.

Radiation, however, has side effects, potentially leading to more frequent bowel movements, flatulence and rectal incontinence -- as well as potential impotence in men and vaginal damage in women. Newer forms of radiation therapy using computer-controlled techniques and 3-D imaging can reduce some of these side effects.

It's a testament to your friendship that your friend was finally able to share her diagnosis with you. By seeking to learn more about anal cancer, you're not only showing concern, but also helping raise awareness.

Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.